In many circumstances it is desirable to have a compact or portable heating device for heating food, beverages or other items when a conventional oven or stove is unavailable. For example, a portable heating device may be useful to people who camp or backpack and need a convenient way to heat food items wherever they may find themselves. Similarly, it is common to find construction sites or remote work sites where no utilities are provided or no appliances are installed. In other situations, such as a natural disaster or a power outage, an existing cooking appliance may be inoperable. A portable heating device may be employed on such rare occasions and yet may be easily stored out of the way during the majority of the time when it is not needed.
To facilitate being used in these ways, it is desirable to provide a heating implement that is portable, lightweight and compactly stored. It is also desirable that the unit operate independently of any particular immobile supply of energy such as an electrical wall socket or a natural gas line.
A number of portable heating devices have been commercially available or proposed by others, offering various degrees of compactness and suitability for various types of use. These are typified by U.S. Pat. No. 4,508,096 to Slattery, U.S. Pat. No. 5,713,344 to Gilbert, U.S. Pat. No. 5,119,799 to Cowan and U.S. Pat. No. 1,411,596 to Tallman.